/// <summary>
/// Used by logic planner to update the list of ReferencedFields
/// </summary>
internal virtual void PropagateReferencedPropertiesForEntityFields()
{
// lift the referenced fields from the next layer of operators back to this one's output entity fields
var referredFieldsInDownstreamOps = OutOperators.SelectMany(op => op.InputSchema)
.Where(f => f is EntityField)
.Cast <EntityField>()
.GroupBy(f => f.FieldAlias)
.ToDictionary(kv => kv.Key, kv => kv.SelectMany(fn => fn.ReferencedFieldAliases).Distinct().ToList());
foreach (var field in OutputSchema.Where(f => f is EntityField).Cast <EntityField>())
{
Debug.Assert(referredFieldsInDownstreamOps.ContainsKey(field.FieldAlias));
field.AddReferenceFieldNames(referredFieldsInDownstreamOps[field.FieldAlias]);
}
// lift the referenced fields in the entity fields from output to input schema of this operator, if
// applicable
if ((InputSchema?.Count ?? 0) > 0)
{
// handle entity name renamed cases by creating a map from field alias before projection to after
// projection
var aliasMap = new Dictionary <String, String>();
if (this is ProjectionOperator)
{
var aliasMap1 = (this as ProjectionOperator).ProjectionMap
.Where(u => OutputSchema.Where(n => n is EntityField).Any(k => k.FieldAlias == u.Key));
aliasMap = aliasMap1?.ToDictionary(n => n.Value.GetChildrenQueryExpressionType <QueryExpressionProperty>().First().VariableName, n => n.Key);
}
else
{
// create a dummy alias map ( A -> A, B -> B; not alias name modified) for non-projection operator
aliasMap = OutputSchema.Where(n => n is EntityField).ToDictionary(n => n.FieldAlias, n => n.FieldAlias);
}
foreach (var field in InputSchema.Where(f => f is EntityField).Cast <EntityField>())
{
var mappedAlias = (aliasMap.ContainsKey(field.FieldAlias) ?aliasMap[field.FieldAlias]:null);
if (mappedAlias != null && referredFieldsInDownstreamOps.ContainsKey(mappedAlias))
{
field.AddReferenceFieldNames(referredFieldsInDownstreamOps[mappedAlias]);
}
}
var referredFieldsForUpstream = InputSchema
.Where(f => f is EntityField).Cast <EntityField>()
.ToDictionary(kv => kv.FieldAlias, kv => kv);
// Some operators has additional fields may get referenced even they are not in output schema
// Such as in WHERE or ORDER BY
// Child logical operator class implement this and does the appending
AppendReferencedProperties(referredFieldsForUpstream);
}
}
protected override Delegate[] CreateGetters(DataViewRow input, Func <int, bool> active, out Action disp)
{
var bindings = GetBindings();
IEnumerable <DataViewSchema.Column> inputColumns;
Func <int, bool> predicateMapper;
IEnumerable <DataViewSchema.Column> activeColumns = OutputSchema.Where(col => active(col.Index));
GetActive(bindings, activeColumns, out inputColumns, out predicateMapper);
var output = bindings.RowMapper.GetRow(input, predicateMapper);
Func <int, bool> activeInfos = iinfo => active(bindings.MapIinfoToCol(iinfo));
disp = output.Dispose;
return(GetGetters(output, activeInfos));
}
